https://github.com/vorpalblade/prefix-range

Compute bounds for prefix string queries for BTreeSet/BTreeMap::range
https://github.com/vorpalblade/prefix-range

Last synced: 9 days ago
JSON representation

Compute bounds for prefix string queries for BTreeSet/BTreeMap::range

• Host: GitHub
• URL: https://github.com/vorpalblade/prefix-range
• Owner: VorpalBlade
• License: mit
• Created: 2024-01-14T08:39:14.000Z (10 months ago)
• Default Branch: main
• Last Pushed: 2024-10-14T11:16:23.000Z (about 1 month ago)
• Last Synced: 2024-10-20T00:55:53.591Z (27 days ago)
• Language: Rust
• Size: 30.3 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# Compute bounds for prefix string queries for BTreeSet/BTreeMap::range

[ [crates.io] ] [ [lib.rs] ] [ [docs.rs] ]

If you have a BTreeSet or BTreeMap with string keys and want to find all entries

with a given prefix, the standard library (as of Rust 1.75) doesn't offer any

built in methods to do so.

You could use something like the following:

```rust

let iterator = mymap.range(Bounds::Included("myprefix"),

                           Bounds::Excluded("myprefiy"));

```

This issue is finding the upper bound `myprefiy`. You have to deal with UTF-8

encoding, invalid code points etc. That is what the code in this library solves.

The code is taken from [a blog post by Jimmy Hartzell](https://www.thecodedmessage.com/posts/prefix-ranges/),

and slightly tweaked:

* To work in no-std (still needs alloc though)

* To work with BTreeMaps (not just BTreeSets).

A huge thanks to Jimmy Hartzell for solving the problem already (though they

never published it as a crate reusable by others).

See the [crate documentation][docs.rs] for usage examples.

## MSRV

The code is simple, and will likely compile on quite old versions, though

nothing older than 1.65 is being actively tested.

[crates.io]: https://crates.io/crates/prefix-range

[docs.rs]: https://docs.rs/prefix_range

[lib.rs]: https://lib.rs/crates/prefix-range